Negativity captures attention and motivates people to read and share news, but can also harm mental health and sometimes discourage action to address long-term problems like climate change. Negative affect also has complex effects on memory—for example, focal details may be enhanced, but peripheral details can be distorted or forgotten, leaving individuals vulnerable to future misinformation. Here, we investigated an alternate route to increasing engagement with news: evoking positive affect by emphasizing opportunity and progress toward future goals. In two experiments, we adapted environmental news headlines to feature different aspects of each story, emphasizing Crisis or Opportunity. Both Crisis and Opportunity framing (and negative and positive affect, respectively) motivated reading and sharing, relative to the unaltered headlines. Crucially, consistent with theoretical predictions, we identified a trade-off: Crisis framing had the strongest effects on immediate engagement (increasing sharing and real charitable donations), but impaired memory for peripheral details; in contrast, Opportunity framing enhanced memory for news content. In a third study, we investigated real-world engagement with news about climate change by computationally classifying content in >25,000 news headlines on social media; Opportunity and Crisis framing were both associated with increased likes, reposts, and replies. Overall, we demonstrate that the affective framing of news modulates reading, sharing, donations, and memory in laboratory and real-world settings.